US3870007A

US3870007A - Rudder control cable system

Info

Publication number: US3870007A
Application number: US405042A
Authority: US
Inventors: John F Morse
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-10-10
Filing date: 1973-10-10
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11

Abstract

A marine push-pull cable system for transmitting steering force from a steering control to an oscillatable rudder arm in which both ends of the cable core are connected to the rudder arm at spaced pivots along the arc swung by the arm, the cable core defining a substantially straight line path passing through a selected position of said pivots, and the varying distance between the pivots in said straight line direction compensating for the change in cable core path as the arm oscillates.

Description

United States Patent 1191 Morse 1 Mar. 11, 1975 1 1 RUDDER CONTROL CABLE SYSTEM [76] Inventor: John F. Morse, 1699 Hines Rd.,

Hudson, Ohio 44236 221 Filed: Oct. 10, 1973 211 Appl. No.: 405,042

[52] U.S. Cl. 114/160, 114/144 R [51] Int. Cl. B631! 25/10 [58] Field of Search 114/144 R, 160, 154;

115/35, 18 R; 74/480 B, 501 R [56] References Cited UNITED STATES PATENTS 1,403,318 l/1922 Hansen 114/160 1,711,126 4/1929 Parsons... 3,164,122 1/1965 Fageol 3,208,300 9/1965 Morse 3,266,454 8/1966 Sterling et al 115/35 Primary ExaminerTrygve M. Blix Assistant Examiner-Gregory W. OConnor Attorney, Agent, or Firm-Hamilton, Renner & Kenner [57] ABSTRACT A marine push-pull cable system for transmitting steering force from a steering control to an oscillatable rudder arm in which both ends of the cable core are connected to the rudder arm at spaced pivots along the arc swung by the arm, the cable core defining a substantially straight line path passing through a selected position of said pivots, and the varying distance between the pivots in said straight line direction compensating for the change in cable core path as the arm oscillates.

6 Claims, 7 Drawing Figures PATENTEUHARI I IHYS 3,870007 sum 10E 5 PAIENI MARI 1 ms SHLU 2 0F 5 m wE FATEHTED W I 7 SHKU 3 0F 5 PATENTED 1 1975 3. 8.70.007

SHEET t UF- 5 1 RUDDER CONTROL CABLE SYSTEM BACKGROUND OF THE INVENTION Various arrangements of flexible push-pull cables have been used to transmit steering forces from a marine steering head or control to an oscillatable rudder arm. One simple conventional arrangement has means driving the cable core at or near one end with the other end pivoted to the rudder arm and the cable casing swiveled to the boat structure adjacent to the rudder arm.

A more recent conventional arrangement utilizes a closed loop of cable in which both ends of the cable are connected toa common pivot on the rudder arm and the adjacent ends of the cable casing are swivel mounted on the boat structure. This provides a pushpull cable system of substantially increased capacity. However, since these flexible cables are designed and manufactured to allow motion to be transmitted by the cable core with a minimal amount of elasticity and backlash to give maximum efficiency, a serious prob lem of increased tension load and bind-up on the cable core arises due to the change in length in the cable path caused by the arcuate swing of the rudder arm. In other words, the path of the cable core between the two swivels anchoring the casing-to the boat structure follows a straight line in one position of the rudder arm but necessarily deviates and becomes a longer path as the arm swings through its arc.

Attempts have been made to alleviate this problem by passing the straight line path of connection through various positions on the arc of the rudder arm, but these have resulted only in shifting the increased load and attendant binding on the cable core from one position of the rudder arm to another. Thus, when the straight line path is tangent to the arc of the rudder arm at its medial or dead ahead steering position a condition of maximum binding is produced at the extreme positions of the rudder arm arc, and when the straight line path passes through the extreme positions of the arc a condition of maximum binding is produced at the A preferred arrangement comprises connecting the ends of the cable core to the two pivots on the arm with the straight line path between the swivel mounts passing substantially through the pivots in the extreme positions of the arm, so that the straight line distance be tween the pivots increases as the arm swings to medial or dead ahead position to compensate for the increase in length of the path of the cable core.

.The objects of the present invention are accomplished by the improvements comprising the present invention, preferred embodiments of which are disclosed in the accompanying drawings and described in detail in the following description. Various modifications and changes in details of construction are intended within the scope of the appended claims.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a closed loop cable operatively connected to a steering head, with the ends of the cable casing swiveled on the boat structure, and the ends of the cable core connected to spaced pivots on the free end of a rudder arm in the medial position of its arc.

FIG. 2 is an enlarged rear elevation, partly broken away and in section, of the steering head.

FIG. 3 is an enlarged partial view similar to FIG. 1 showing the rudder arm in medial position.

FIG. 4 is a similar view showing the rudder arm swung to an angle of from its medial position.

FIG. 5 is a diagrammatic view showing typical radii and dimensions of the parts and connections in the podead ahead position. As a consequence, certain cable manufacturers recommend that the straight line connection be made at a position 10 from the dead ahead position so as to produce minimal binding within the ordinary steering range of 15 to either side of dead ahead position and somewhat less than maximum binding at the extreme positions, thus shifting what is regarded as the unavoidable binding condition to the least objectionable position of the rubber arm.

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide a simple and inexpensive connection between the two ends of a closed loop cable transmitting motion from a steering control and a rudder arm such that the length of the cable path does not change appreciably as the rudder arm swings through its are from one extreme to the other.

This is accomplished by swivel mounting the two ends of the cable casing on the boat structure adjacent to and on opposite sides of the rudder arm and connecting the ends of the cable core to two pivots on the free end of the arm spaced apart along its arc a distance which will compensate for the change in the cable path from the straight line direction between the swivel mounts caused by the swing of the arm through its arc.

sitions of FIGS. 3 and 4.

FIG. 6 and 7 are partial views similar to FIGS. 3 and 4 showing the manner of connecting the ends of the cable core to a rudder arm which swings 45 from its medial position.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring first to FIGS. 1 and 2, the steering head comprises a housing 10 enclosing a ring gear 11 journaled on an axial hub in the housing. A pinion gear 12 mounted on the steering post of a steering wheel 13 meshes with the ring gear and the steering post is journaled in an offset part 14 of the housing.

The ring gear 12 is provided with an annular pulley flange 15 axially spaced from the gear teeth and the exterior annular surface of the flange has helically disposed grooves for engaging the outer helical wire wrap 16 of the cable core 17 which is of conventional construction. The outer annular face of the cable is slidably engaged within the housing bya guide tube 18 preferably of plastic material.

The construction of the cable core 17 may be varied in accordance with various conventional constructions, and obviously the pulley flange would be varied accordingly. The construction of the steering head per se forms no part of the present invention.

The casing 20 for the cable core 17 is also of conventional construction and comprises a plurality of circumferentially arranged wires usually having a long lay or pitch and covered by a flexible protective sheath of plastic material. The tubular portions 22 of the housing through which the cable passes are adapted to hold fittings 23 gripping the ends of the outer sheath of the cable casing 20.

Thus, an intermediate portion of the; cable core 17 is formed into a loop passing around the pulley flange and rotation of the steering wheel causes the pinion 12 to drive the ring gear 11 and with it the cable core engaged by the pulley flange 15. From the steering head housing the two cable portions are extended around the boat structure in a usual manner to the proximity of the rudder arm indicated at 25 to which the opposite ends of the cable core 17 are pivotally connected to form a closed loop as indicated in FIG. 1.

On opposite sides of the rudder arm the end portions of the cable'casing are swivel mounted on the boat structure at equal distances from the arm. As shown in the drawings, the ends of the cable casing 20 are secured in metal bushings 26 which are in turn secured or staked in metal sleeves 27, the sleeves27 having corrugated portions on which ball swivels 28 are clamped by spherical brackets 29. The bases of the brackets are mounted on the boat structure indicated at 30, which may be a wall of the transom.

Referring to FIG. 3, the opposite ends of the cable core 17 are swaged or otherwise connected to terminal rods 31a and 31b which telescope within the sleeves 27 and have

clevises

32a and 32b, respectively, on their outer ends. Preferably, soft rubber bushing seals 33 fit over the outer ends of the sleeves.

In the conventional closed loop cable system the clevises are both connected to a commonpivot on the free end of the rudder arm 25, the other end of which is pivoted at 35 to a bracket 36 on a wall 30' on the transom. The rudder arm is rigidly connected in a usual manner to the rudder indicated schematically at 37. The displacement of the pivotal connection between the clevises andthe rudder arm necessarily varies the length of the path of the cable core as the rudder arm swings arcuately around its pivotal mounting, and a serious problem of increased tension load and binding on the cable core results.

According to the present invention, the position of the rudder arm between the swivel mounts 25 is oriented so that a straight line passing through the swivel mountsintersects the are 41 swung by the rudder arm at the extreme positions of the arm, and the

clevises

32a and 32b are connected to two

pivots

40a and 40b, respectively, which are spaced apart along the arc. Referring to FIG. 3, the straight line 42 between the swivel mounts substantially intersects the extreme 35 swing positions of the arc of the rudder arm, and the two

pivots

40a and 40b straddle the 0 or medial dead ahead position of the rudder arm.

As shown in FIG. 4, when the rudder arm is swung to one-of the extreme 35. rudder arm positions, in this case the left position, the arm 31a is retracted within its sleeve 27, and the arm 31b is extended. The swing of the rudder arm pivots 40a and40b along the are 41 of the rudder arm angles the pivots with respect to the straight line 42 and decreases the distance between the pivots in that direction, thus compensating for the change in the length of the path of the cable core as the terminal rods 31a and 31b and their sleeves 27 swing about their swivel mounts to follow the arc of the rudder arm.

Referring to the diagrammatic view, FIG. 5, the rareduced from 1% inche's-atthe medial position to 1 5/16 inches at the extreme positions which compensates for the displacement'of the terminal rods 31a and 31b as they swing about the swivels 28.

The distance between the swivel mounts 28 is determined by the available beam space in the boat, the distance which the terminal rods telescope within the sleeves, and the lack of stability of the assembly between swivel mounts if they are too farapart. In the example depicted in FIG. 5, the distance between the swivels 28 and the rudder arm pivots to which the terminal rods 31a and 31b are connected is l8/2 inches and the telescoping travel of the rods in the sleeves 27 is 12 inches. Thus, from the medial position of FIG. 3 to the 35 left position of FIG. 4, rod 31a is retracted 6 inches in its sleeve to make the overall length from swivel to pivot 40a 12% inches, and rod 31b is extended 6 inches to make the overall length from swivel to pivot 40b 24 /2 inches, and the total cable travel between the two extreme positions is therefore 12 inches.

In FIG. 5 it will be seen that if the two pivot points 400 and 40b were swung downwardly about the swivels 28, the distance between their arcs where they intersect line 42 is 1 inches, and this distance is exactly the same as that between the

pivots

40a and 40b at the 35 positions of the rudder arm because in those positions one terminal rod retracts the same distance as the other rod extends.

It has been determined that for a rudder arm having a 10% inches radius and terminal rods having an extended overall length of 24 /2 inches from the swivel mounts and a retracted length of 12 /2 inches, the

pivots

40a and 40b should be spaced apart a chordal distance of 1% inches on the rudder arm arc, giving a distance of 1 5/16 inches in the direction of a straight line between the swivel mounts which compensates for the change in direction of the path of the cable core during the swing of the arm 35 to each side of the medial positions, thus maintaining the length of the cable core substantially constant and eliminating tension loads and binding thereon.

In FIGS. 6 and 7, the connections between the swivel mounts 28 and the

pivots

140a and 14% are shown for a rudder arm which swings 45 to each side of the medial dead ahead position. In this case the straight line 42 between swivels 28 intersects the outer one of the pivots a and 140b at the extreme 45 positions,

as shown, and the radius of the rudder arm is shortened so that the telescoping travel of the terminal rods 131a and 131k remains the same. A swing of the rudder arm in excess of 45 is not usually desirable or necessary.

It is obvious that the results achieved by the constructions of FIGS. 1-7 can be achieved by passing the straight line between the swivels tangent to the rudder arm are at the medial position of the arm, and crossing the terminal rods to connect to the opposite pivot points on the arm, using ball joints above and below the arm, although such construction would be somewhat more complicated.

The rudder control cable system shown and described herein providesa simple and inexpensive connection between the two ends of a closed loop cable transmitting steering motion to a rudder arm in a manner such that the length of the cable path does not change as the arm swings through its arc and tension loads and binding on the cable core is virtually eliminated. The system is applicable to a range of rudder arm travel within desirable limits.

I claim:

1. In a boat structure having an oscillatable rudder arm which swings arcuately about one end from a medial steering position to extreme turning positions at the ends of its arc, a remote steering control, and a closed loop push-pull cable including a casing and cable core for transmitting motion from said steering control to said rudder arm and having opposing ends of said casing swivel mounted on the boat structure adjacent the rudder arm, the improvement comprising means connecting the two ends of the cable core in a substantially straight line path between said swivel mounts at a selected position on the arc of the arm to two pivots on the free end of said arm, said pivots spaced apart on the arc of said free end a distance which compensates for the change in the cable core path as the arm swings through its arc.

2. In a boat structure as described in claim 1, in which the straight line path between the swivel mounts passes substantially through an outer pivot of said two pivots in the extreme positions of the rudder arm.

3. In a boat structure as described in claim I, in which the extreme positions of the rudder arm are at least 35 from its medial steering position.

4. In a boat structure as described in claim I, in which the extreme positions of the rudder arm are from 35 to 45 from its medial position.

5. In a boat structure as described in claim 2, in which the extreme positions of the rudder arm are at least 35 from its medial steering position.

6. In a boat structure as described in claim 2, in which the extreme positions of the rudder arm are from 35 to 45 from its medial position.

Claims

1. In a boat structure having an oscillatable rudder arm which swings arcuately about one end from a medial steering position to extreme turning positions at the ends of its arc, a remote steering control, and a closed loop push-pull cable including a casing and a cable core for transmitting motion from said steering control to said rudder arm and having opposing ends of said casing swivel mounted on the boat structure adjacent the rudder arm, the improvement comprising means connecting the two ends of the cable core in a substantially straight line path between said swivel mounts at a selected position on the arc of the arm to two pivots on the free end of said arm, said pivots spaced apart on the arc of said free end a distance which compensates for the change in the cable core path as the arm swings through its arc.

3. In a boat structure as described in claim 1, in which the extreme positions of the rudder arm are at least 35* from its medial steering position.

4. In a boat structure as described in claim 1, in which the extreme positions of the rudder arm are from 35* to 45* from its medial position.

5. In a boat structure as described in claim 2, in which the extreme positions of the rudder arm are at least 35* from its medial steering position.